Theater audiences continuously seek out larger displays with greater resolution. In the motion picture industry this has resulted in a gradual increase in the size of the film format from 16 mm to 35 mm to 70 mm to "IMAX". In the television industry, screens have increased in size so much that projection TVs can now fill an entire wall of an average sized living room.
However, while the larger film formats have brought high resolution, commercial television resolution is limited by the commercial industry broadcast standards. The broadcast standards define both the aspect ratio and the resolution of the image. The broadcast standards limit resolution by defining the number of horizontal lines per frame and the number of picture elements in each line. An increase in the size or horizontal scope of a commercial television image necessarily brings no increase in the number of lines or the number of picture elements in that image. Therefore, a very large picture will not be as sharp and clear as a smaller image. Several commercial-type video signals may be combined to form a single image with a different aspect ratio, with more picture elements, or with more lines per frame. However, this requires either combining several projectors to form that single image, or developing a whole new format different from the commercial standards.
In the film industry there have been several experiments with multiple projector systems. One such experiment was the "CINERAMA" systems of the 1950's. In "CINERAMA," three films, shown through three projectors, were combined to form a single panoramic image. Disneyland and its affiliate parks continue to use a different multiple projector system. At Disneyland, a circle of projectors shine onto a screen that circles the wall of a round room.
In the video field, multiple projector systems have been suggested for flight simulators, see e.g. U.S. Pat. No. 4,103,435 to Herndon, and U.S. Pat. No. 3,833,764 to Taylor. In addition, it is known to place several video screens next to each other to form a large image display from multiple projectors. However, the difficulty with all video based multiple projector display systems is making the multiple images appear to be one single continuous image on the display screen.
When two images are projected side by side on a single screen, there will normally be a seam between the two images. The final display image will either appear to be two images placed side by side with a gap in between or, if the images are made to overlap on a single screen, there will be a bright line where the two images overlap. Because of the inconsistencies in conventional cameras and projectors, it is exceedingly difficult to perfectly match video images with no gap and no overlap between the images. If the images are brought very close together on the same screen, there will likely be both gaps and overlaps at the seam.